Preheat oven to 400 degrees F. Spray a 9x13 baking dish with nonstick spray.
Cover bottom of baking dish evenly with spinach and sprinkle half the cheese on top. Crack the eggs randomly into the dish on top of the spinach and cheese. Sprinkle salt and pepper over eggs, then drizzle heavy cream over the top and finish with the remaining cheese. Bake for 20-25 minutes, depending on how done you like your eggs. If you want a runny yolk, cook for the lesser time. In fact, check them around 15 minutes and see if the whites are cooked through.
Once the eggs are finished, remove from the oven and allow to cool for a couple of minutes before using a spatula to cut into squares. Place toasted bread pieces on plates and top with one or two of the egg squares. Top with parsley, if desired and serve immediately.